Pile fabrics from nonwoven fabrics



Dec. 17, 1968 A. Bo'rToMLl-:Y

PILE FABRICS FROM NOWOVEN FABRICS 2 Sheets-Sheet 1 Filed Jan. 18, 1965 KmnEOIU WDODZTrZOUm-D l L J INVENTOR ANTHoNY BoTToMLEY .rmmIw @O 0254302 A T TORNEVS v Dec. 17, 1968 A. BoTToMLEY PILE FABRICS FROM NONWVEN FABRICS Filed Jan. 18. 1965 2 Sheets-Sheet 2 NVENTOR.

ANTHONY BOTTOMLEY A T TOR/v5 ys United States Patent O 3,416,299 PILE FABRICS FROM NONWOVEN FABRICS Anthony Bottomley, Maplewood, NJ., assignor to Phillips Petroleum Company, a corporation of Delaware Filed Jan. 18, 1965, Ser. No. 426,130 8 Claims. (Cl. 57-31) ABSTRACT OF THE DISCLOSURE Method and apparatus for forming a pile fabric from a plastic film comprising orienting the film, partially disintegrating same, folding out the partially disintegrated film, and then randomly severing interconnected fibers of the partially disintegrated film to produce a bulky, nonwoven fabric,

The present invention relates to a novel method and apparatus producing nonwoven pile fabrics from continuous sheet material. In one aspect the invention relates to an apparatus for producing a fleecy, nonwoven fabric from split oriented thermoplastic material. In another aspect, the invention relates to a process for producing nonwoven fabrics possessing a high percentage of loose fibrils along surface of the fabric.

It is well known that many synthetic organic linear polymers possess a very marked fissility when they have been uniaXially oriented to a high degree. An existing method makes use of this property in the manufacture of threads and fibers which are formed by splitting highly oriented thermoplastic materials, usually foils or films. The disintegration is carried so far as to form single threads or fibers by brushing, rolling, rubbing, twisting, grating, impacting or striking the oriented sheet material.

This type of mechanical Working partly disintegrates the film to form an open network in the sheet. The term sheet as used herein includes strips and tubular foils. It is typical of such sheets that although the fibers form an open network they tend to draw closely together whenever the material is brought under longitudinal tension. The yarn made from such a fibrous product can be spread out to increase the space between the fibers and held in this state while being twisted and cross-laminated with multiple plies of the same material. The friction between the associated fibers tends to keep the mesh in the extended state so that the yarn or fabric is more voluminous than would otherwise be the case. In this portion, the individual fibrils are parallel to the axis of the sheet and their surfaces -are lean and smooth.

According to the present invention, the individual fibers in the sheet material are severed in random fashion to produce a high percentage of loose fibrils on the surface of the sheet. This severing step is performed upon the sheet material after the highly oriented sheet material has been disintegrated to form a network of interconnected fibers and folded out to the dimension of the sheet. These severed individual fibrils will spring away from the main body of the sheet material because of their having been stretched by the folding out step to form a bulky rather than a smooth fabric. For certain textile products, such as carpets, blankets, and other such woolen fabrics, it is essential that the yarn employed in their production be made from a bulky or pile fabric. The pile fabrics produced according to the method described hereinbelow would have a longer life than a conventional pile fabric made from wool or the like because the pile fibers of the subject disclosure are firmly anchored to the sheet material whereas the surface fibers in conventional pile fabrics are not securely anchored to a backing material.

The essential steps of the invention are, therefore, disintegrating a highly oriented sheet material to a point ACC at which the material is still coherent so as to form a network of interconnected fibers, folding out the fibrous Iletwork to the dimensions of the sheet, and severing these interconnected fibers in random fashion so as to not significantly weaken the sheet material.

An object of this invention is to produce a novel, bulky, nonwoven fabric.

Another object of the invention is to produce a pile fabric without causing substantial loss in the overall strength of the fabric.

Another object of the invention is to produce a nonwoven fabric in which different areas of the same fabric display different qualities and physical characteristics.

A further object of this invention is to provide a fieecy, nonwoven fabric which is highly resistant to fray and ravelling.

A still further object of the invention is to produce a mechanically strong, nonwoven fabric having properties which lare similar to conventional fabrics made from wools, cottons, and the like.

A still further object of this invention is to provide a process for producing a fieecy, nonwoven fabric.

A still further object of this invention is to provide apparatus for producing a fleecy, nonwoven fabric.

Other objects and many of the more salient characteristics of this invention will be readily -appreciated and understood by reference to the following detailed description which is considered in connection with the `accompanying drawing wherein:

FIGURE 1 shows a flow sheet of the method according to the present invention.

FIGURE 2 shows a diametric view of an apparatus for producing ruptures in the individual fibers in the oriented sheet whereby a degree of bulkiness is achieved along the surface of the sheet.

FIGURE 3 is a view taken along line 3-3 of FIG- URE 2 with the side plate removed and the drive means not shown.

FIGURE 4 is a front view shown partly in section of another embodiment of the apparatus described in FIG- URE 2.

FIGURE 5 shows a front view of another embodiment of the apparatus described in FIGURE 2.

FIGURE 6 shows a diametric view of another embodiment of the apparatus described in FIGURE 2, showing the ruptured sheet being twisted onto a spool.

In FIGURE 1 there is shown a flow sheet which diagrammatically illustrates the main steps of this process. The patent of Ole-Bendt Rasmussen, No. 3,003,304, teaches that a molecular orienting can be imparted to a number of high molecular weight polymers, particularly linear high molecular weight polymers, by stretching which is generally best done while heating the polymer to a temperature close to its melting point. It is also known that the resulting orientation clearly facilitates the fibrillation of the systems by a mechanical or chemical action. The fibrillation of the polymer is easier when the degree of `orienting is higher, and it is, therefore, advantageous to employ a high degree of orienting to the systems by stretching as much as possible.

The oriented sheet disintegration (the third step in the process), may be carried out in different ways. Several methods of disintegrating the oriented sheet may be achieved. These methods are taught in the above-identified patent. This disintegration of the highly oriented sheet material is stopped at an intermediate state at which the material is still coherent, forming a network of interconnected fibers. This fiberwork must be folded out. This can, for instance, be done by charging the fibrils electrically and, if desired, giving them a mild mechanical treatment during the action of the electrical forces. The

mild mechanical treatment may, for instance, consist of striking, rubbing, brushing, or vibrating. Such treatment during the electrical treatment will not only `fold out but also spread the material ont.

At this point in the flow sheet of FIGURE 1 the sheet material is in a spreadout condition wherein the individual fibrils, making up the material, are parallel to the longitudinally axis of the sheet material. In many cases, :and for many applications, this is a desirable configuration. However, for certain textile products the yarn used in the manufacture therein should not be lean and smooth but rather should have 'a high percentage of loose'fibrils along the surface of the web or sheet as the case may be. For instance, in the case of blankets, carpets, and fabrics made from woolen yarns, it is essential to use a bulky yarn which is not produced under the process described in the above-identified patent.

My invention resides in for-ming a pile fabric from this polymeric sheet material as it emerges from the foldingout step.

With reference to FIGURES 2 and 3, after the sheet material has been folded out as described hereinabove, it passes between -a pair of generally cylindrical rollers 12 and 13, which are rotatably mounted in frame plates 14 and 16 respectively. These frame plates 14 and 16 extend vertically from a base plate 18 which is mounted on wheels 20. This unit is able to be wheeled into a position to receive the film 10 `directly from the folding-out step described in FIGURE 1 in the event that it is desirable to make the whole process continuous. The sheet or web 10 passes from the rollers 12 and 13 to a roller 54 (see FIGURE 6) which is also rotatably mounted in plates 14 and 16.

With reference to FIGURE 6, -a plurality of rollers 54 are shaped to form a crown 56 at their centers. As a result, the fibrils in the central portion of film 10 passing over the crown 56 will break while those in the edge portion of the film passing over the edge of the roller will not. This action of crowned rollers 54 (FIGURE 2) causes the fibrils in the center portion of sheet 10 to break. This web is particularly useful in making yarn and 'as such it is twisted by conventional yarn twisting means as it is wound onto a spool 58.

As shown in FIGURES 2 and 3, rollers 13, 54 (only one roller is shown; however, it would be Within the skill of the art to connect a plurality of crowned rollers into the mechanism) and 29 are connected to a suitable driving mechanism 30. This mechanism comprises an endless belt or chain 32 which passes over a pulley or sprocket 34 which is fixed to roller 54, then over a sprocket 36 which is fixed to roller 13, then over a sprocket 38 which is fixed to roller 29, then over an idler sprocket 40, then over a drive sprocket 42, which is driven by any suitable power source such as electric motor 44, and finally back over sprocket 34. The rollers 12, 13, 54, 28, and 29 are rotated in the directions shown by the arrows.

With reference to FIGURE 4, roller 22 is provided with a plurality of grooves 24 and a plurality of needles 26- or other similar sharp, pointed implements, which project radially from the center of the grooves 24. These needles may be secured in the grooves 24 in any suitable manner. As the sheet 10 passes over the roller 22, portions of it are channelled into the grooves 24 and become impaled upon the needles which penetrate through the sheet material and cause a portion of the individual fibrils to be severed. The degree of breakage would be determined by the number of grooves in the roller and the number of pins in the grooves; however, no more than one-half of the fibers passing over the roller should be broken in order to retain suiiicient web strength. In the preferred embodiment we show only 4one roller but it would be within the skill of the art to adapt a plurality of rollers over which the film could be passed. The film after passing over the pin-studded froller 22 is received by a pair of pick-up rollers 28 and 29 which are also rotatably mounted in the frame plates 14 yand 16. These rollers feed the bulky sheet material to a suitable take-up mandrel (not shown).

FIGURE S illustrates another embodiment of my invention. In this embodiment a roller 46 contains a plurality of grooves 48 around the perimeter thereof. These grooves are cut at `an angle of 45 to the horizontal axis 50 of the roller 46. This roller 46 is attached to frames 14 and 16 in place of roller 22. A plurality of knife blades 52 are positioned around `the circumference of roller 53 rotatably mounted between the Vertical frames 14 and 16 a predetermined distance from roller 46. The sheet 10 is passed between the roller and the blade. The blade 52 is rotated in close enough proximity to the roller 46 so that portions of the film 10 pass over the crown of the grooves 48 and are cut by the rotating blades 52. Because of the angle of inclination of these grooves a discontinuons chopping of the individual fibrils results without cutting entirely across the sheet itself. The strength of the sheet itself is not significantly affected. This fabric possesses a tremendous advantage over a normal pile fabric because the pile fibers form an integral part of the sheet and are firmly anchored to the surface of the sheet.

In order to illustrate with greater particularity and clarity the operation of my process, the following examples -are offered as illustrative of the operation thereof. The specific materials and conditions given in the examples are presented as being typical and should not be construed to limit my invention unduly.

EXAMPLE I A 60inch wide brillated web of 0.8 mil polyethylene, having -a density of 0.95 gram/cc. and a melt index of 0.3 (ASTM D 123 8-5DT, Condition E), is threaded through the machine described in FIGURE 2. A chopper roller 53 is provided with l2 tempered spring steel blades 52 around its circumference. The blades 52 coact with a 12-inch diameter grooved roller 46, made of mild steel and coated to a thickness of 60 mils with 80 durometer rubber. Each groove 48 in roller 46 defines an ellipse in a plane making a 45 angle with the roller axis. These grooves are 14s-inch wide, 1As-inch deep, and spaced so that their centers are 1r-inch apart, and having all their edges and corners chamfered and rounded on a 1/winch radius. Bulk film is fed to roller 12 at the rate of 20 feet per minute while the machine is being adjusted to insure clean, uniform cuts. After adjustment, the rate is increased to `feet per minute and about 2000 feet of the material is fed through the machine.

Air lters 21/2 feet square are produced from some of this material -by laminating 21 layers of this bulked film together, each layer being laid at right angles to the adjacent layers 21 and being stitched together in both directions across lthe film at 6-inch intervals with cotton string and subsequently edged with an aluminum channel having a 1s-inch flange.

In another application ten 8-foot sections of this bulked fibrilated web are stitched together on 4-inch centers both lengthwise and crosswise and the edges bound to make an exceptionally warm, lightweight blanket.

Example 1I The rollers 46 and 53 are replaced with a 12-inch diameter pin-studded roller 22 similar to that shown in FIGURE 4. The grooves 24 are 1/2-inch centerto-center with a sharp 60 included angle peak between the grooves. In each groove 36 equally spaced cylindrical pins 26 are positioned wherein each pin is W32-inch in diameter and has a fiat, sharp edged top portion located '07,2-inch below the peaks. Web material similar to that used in Example I is threaded through the machine and the machine is started and run at an initial rate of about 15 feet per minute output while adjustments of the film tension over the pinstudded roller 22 are made. After adjustment, the rate is increased to 150 feet per minute to produce approximately Example III In this example, roller 54 is positioned between the end plates 14 and 16 in place of roller 22. A 4-inch wide web of 0.8-mil polyethylene having a density of 0.95 gram/cc. and a melt index of 0.3 (ASTM D 1238- DT, Condition E) is threaded through rollers 12 and 28 so as to pass over roller 54. Roller 54 is -a 6-inch long roll with a center diameter of 6 inches and smoothly tapered to end diameters of 1 inch. The material is run at an initial rate of 5 feet per minute during tension adjustment and increased to 50 feet per minute. Mos-t of the fibrils in the center portion of the band of the web 10 extending to within approximately l inch of the edge portion are broken. The resulting band is spooled and subsequently twisted into -a bulky 1.8-inch diameter strand by a conventional Warner and Swasey Whirlwind Twister Winder as shown in FIGURE 6.

It will -be understood that the invention is not to be limited to any special group of organic synthetic linear polymers. Materials which have been oriented and split up successfully to form a network are, for instance, polyamides, polyurethanes, polyesters, esters and anhydrides, polyethers, and polyanhydrides, mixed polymers of these compounds, polyethylene, polypropylene, rubber hydrochloride, polyacrylonitrile, polymerishes of vinylidene chloride, styrene, vinylchloride, vinylacetate, and the like.

I claim:

1. A method of producing nonwoven pile fabrics from sheet material, said method comprising the steps of partially splitting an oriented sheet material formed from a synthetic polymer so -as to produce a network of fibers which are mutually interconnected throughout the sheet; subsequently spreading out said network into a fiat band of fibers which are mutually interconnected, and randomly breaking a substantial number of those interconnected bers in a manner which does not significantly weaken the sheet material.

2. A method of producing nonwoven pile fabrics from sheet material, said method comprising the steps of partially splitting an oriented sheet material formed from a synthetic polymer so as to produce a network of fibers which are mutually interconnected throughout the sheet; subsequently spreading out said network into a at band of fibers which are mutually interconnected; penetrating said fibers with a plurality of pointed implements; moving the penetrated fibers whereby said lpenetration and movement cooperates to randomly break a substantial number of the interconnected fibers without significantly weakening the sheet itself.

3. A method of producing a nonwoven pile fabric from (sheet material, said method comprising the steps of partially splitting an oriented sheet material formed from a synthetic polymer, so as to produce a network of fibers which are mutually interconnected throughout the sheet; subsequently spreading out said network into a at band of fibers which are mutually interconnected, and randomly breaking a substantial number of those interconnected fibers which are situated in substantially the center of said sheet material.

4. The method according to claim 3 wherein after said random breaking step said sheet material is twisted to form yarn.

5. Apparatus for producing a non-woven pile fabric from sheet material comprising a frame, feed means carried by said frame forVv feeding sheet material into said apparatus, removal means carried by said frame for removing sheet material from said apparatus, and severing means'carried by said frame intermediate said feed means and said removal means, said severing means l comprising at least one roller means provided with a plurality of grooves, at least one pointed implement extending outwardly from said roller means from inside each of said grooves, said implement projecting outwardly in said groove a distance less than the depth of said groove, said distance being sufficient to cause puncturing of said sheet material as said sheet material is passed over said roller means under tension which causes portions of said sheet material to extend into said grooves.

6. Apparatus for producing a nonwoven pile fabric from sheet material comprising a frame, feed means carried by said frame for feeding sheet material into said apparatus, removal means carried by said frame for removing sheet material from said apparatus, and severing means carried :by said frame intermediate said feed means and said removal means, said severing means comprising at least one roller means having at substantially its center a diameter which is greater than the diameter at its edges, said difference in diameters being suicient to cause fibers at the substantial center of said sheet material to be broken to form a number of loose fibers.

7. An apparatus according to claim 6 further including a means for twisting the sheet into a fibrous yarn.

8. Apparatus for producing a nonwoven pile fabric from sheet material comprising a frame, feed means carried by said frame for feeding sheet material into said apparatus, removal means carried .by said frame for removing sheet material from said apparatus, and severing means carried by said frame intermediate said feed means and said removal means, said severing means comprising at least one roller means having a plurality of grooves, said grooves being cut at an angle of about 45 to the horizontal axis of said roller, and at least one cutting means positioned at a predetermined distance from each of said roller means whereby the sheet material passing over said roller means is randomly cut by said cutting means thereby lcutting a substantial number of fibers in said sheet material.

References Cited UNITED STATES PATENTS 2,853,741 9/1958 Costa et al. 161-168 3,003,304 10/ 1961 Rasmussen.

ROBERT F. BURNETT, Primary Examiner. R. L. MAY, Assistant Examiner.

U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 3,416, 299 December 17, 1968 Anthony Bottomley It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 40, "breaking" should read severing same line 40,

Signed and sealed this 17th day of March 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer 

